Shoe stiffener



Patented Apr. 9, 1929.

UNITED STATES i l wenn PATENT OFFICE.

WILLIAM HAROLD BANOROFT, OF LEICESTER, ENGLAND, ASSIGNOR TO NITED SHOE MACHINERY CORPORATION, OEPATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SHOE STFFENER.

Application led October 18, 1923, Serial No. 669,428, and in Great Britain November G, 192,2.

This invention relates to thermoplastic vstilt'eners for parts of boots and shoes and is herein illustrated as embodied in a toe stillener. Y The term thermoplastic denotes that quality of a substance whereby it is hard and somewhat resilient at ordinary temperatures but may be rendered plastic enough to be molded by subjecting` it to a degree oit heat insutli-cient to injure leather. A toe stiilener of the thermoplastic type and the method of using it is disclosed, :tor eX- ample, in Pat-ent No. 1,124,835.

rlhermoplastic toe stiliiencrs, as heretofore used, have commonly consisted of a blank of f felt impregnated with a thermoplastic agent such, for example, as a mixture of 75 per cent of colophony and25 per cent ot blown asphalt. Such stili'eners are incorporated iii-boots and shoes by inserting them in place in the boot or shoe, heating them to render them limp and plastic, and then molding them toA the desired shape during the lasting` operation. Felt, however, by reason ci its containing necessarily some Wool, is costly; but abrics'eemposed entirely or cotton do not usually provide a stiiiiencr of suilicient strength or stiffness or are not ot suitable character to admit et satistactorily lasting,r the heated limp stillener or else have some other defect from the shoemakers point of view.

lt has been found that stiileners of the kind in question and havinga stillness and strength and other properties generally` equivalent in practicefto a very large degree to those hitherto provided by felt may be produced by the employment of a suitable Woven t'abric napped or lul'led upon both sides; and a Vfeature of the present invention consists in a thermoplastic shoe stitl'ener in which the vehicle for the theri'noplastic substance is such a sheet et labric.

Other features et' the invention will become apparent te those skilled in the art from the ensuing description givenby Way ol example of certain novel forms of stili'- eners.

In the accompanying drawings,

Figure l is a diagrammatic representation of the cross-section of a particular fabric which is advantageously employed in making forms of stiteners according to the invention, the fabric being shown asit appears before the n ap has been raised upon it;

Figure 2 is a diagram oi the tace view of this fabric also before the nap has been raised. ln both these diagrammatic representations the Warp and Wett threads are shown spaced from one another in orderto promote clearness of illustration, although it shouldbe understood that this condition does not obtain in the finished fabric Wherein the threads are drawn taut in the usual manner Figure 3 is a cross-section of the finished fabric Witha nap raised on both sides of it; and

Figure l is aplan of a finished toe still'- ener. u y ,y

The illustrated fabric is a cotton fabric known as filupler: cloth having a double weft and havingl a nap raised upon both sides, preferably of a grade Weighing some 8 to l) ounces persquare yard under ordinary conditions of atmospheric moisture and being about 8 to l2 one-hundredths of an inch this r. This thickness is largely dueto the very considerable raising` of the nap. the Woven material before the nap has been raised having` a thickness oit' but some onelialt of thatv of the finished iabric. The Warp iscomposed of line strongthreads and the Wett or much coarser and more loosely twisted thread, and it is mainly the weft that is raised or tlulled to produce the nap.

In Figures l and 2the thick, loosely twisted weft threads are shown at a and In, and li'our adjacent smaller Warp threads at l, 2, 3, and 4. It should be noted that half ot the weft threads are exposed principally on one side ofthe 'fabric and the other hall principally on the other side. lie- `terring to Figure 2, the wett threads marked a are exposed principally on that side et the fabric which is presented to the observer, While those marked are principally exposed on the side remote trom the observer. The nap on one side of the fabric is raised principally from the threads a While that on the other sideis raised principally from the threads b, comparatively little nap being raised from the finer, harder warp threads. Consequently the napping' or {lulling operation does not greatly weaken the fabric and leaves it possessed of considerable strength, so as to he capable, when impregnated in the manner presently te be described, ci. withstanding the strains of the lasting operation.

`This material may be impregnated in the usual manner by immersion in molten thermoplastic stiffening material having the requisite properties and; well-known in the art, for example the blend ot' asphaltic and resinous materials referred to above. The impregnated sheet, as it leaves the imp reg natiirg` vessel and: while therefore the thermoplastic n'laterial with which it is chargiged, is still more or less fluid, passes between rollers or the like which give itunitorm thickness and will usually be set so as to squeeze the material down to, a thiekness substantially lessI than that which it had Letore impregnation, this action Compacting the soddru napped sides of the sheet. On the other hand, the napped sides can take up andA retain so much, oiu the impregnant that, where a very stili product is desired, the action of the roller or the like may be allowed to be no` more than an eveningv action, and thc product may he of about the thickness of the napped unsaturated material. rl`he impregnated sheet of materialafter cooling is theny cut up into shoe toe stitlener blanks and these may thenbe sk-ived in the nsuaV way if desired. In cutting the blanks it is preferable to cut them, from the sheet in such a, direction that in the blank the warp threads run across the blank from side to side and. the wett therelore runs lengthwise of the shoe when the blank is incorporated therein.

The blanks thus produced from a cheap cotton fabric have, to a remarkable degree, the desirable properties of these made trom the much more expensive Wool felt, it being obsm'ved that the napping;` or raising of both sides of the fabric produces a similarity of conditions from the point of view of capacity for impregnation and oii strength at the opposite sides that renders the iinished blank equally resistant to bending ineither direction and thus renders it wholly immaterial which side of it is v.ippermost in the 'lnished shoe.

An alternative fabric which suitable in many circumstances as an alternative to that just described is the 'fabric known as swansdown but lutled or nappied on both sides instead et being'Y so treated on one side only as is customary forthe purposes to which that article is usually put.

i' avingr thus descriliedmy invention, what l claim as new and: desire to securel by Letters Patent of the Unite(4 States is:

l. ik shoe stitiener consisting oa single sheet oit weven cotton fabric with a niultiple weft, l'uwine'A a nap on beth sides, and impregnated with thermoplastic material..

2. A toe stiitener consisting a. single sheet of woven cotton fabric having a nap en beth sides,` and impregnated with thermoplastic material, said fabric comprising aline, hard Warp and a thicker, softer wett, the warp extendingerosswise ott' the stiffener.

In testimony whereof I have signed my naine to this speciiicatiem` VILLIAM HAROLD BANCRQBW. 

